• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.121-124
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• 2000

The time dependence of irreversible magnetization of grain aligned infinite layer superconductor Sr$_{0.9}$La$_{0.1}$CuO$_2$ was measured in temperature range of 2 K < T < 30 K for H= 0.5 T, 1.0 T and 1.5 T parallel to c-axis. From this, we calculated normalized flux creep rate S(T) ${\equiv}$ dlnM/dlnt and found that the temperature independent region in S(T) is significantly wide in comparision with other cuprate superconductors. Using the method of Maley et al., we also deduce the current density dependence of pinning potential and glassy exponent ${\mu}$.

• Progress in Superconductivity
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• 제4권1호
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• pp.32-36
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• 2002

We have measured the Hall effect in infinite-layer Sr／sub 0.9／La／sub 0.1／$CuO_2$ thin films grown by molecular beam epitaxy. We do not observe $T^{2}$ dependence of the cotangent of Hall angle, which is commonly observed in other cuprate High-Tc superconductors. Therefore, this result cannot be interpreted within two different scattering mechanism based on charge-spin separation theory. The mixed-state Hall effect shows no sign anomaly, implying that tile hydrodynamic contribution of vortex core is negligibly small.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.128-131
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• 2000

We report high pressure synthesis of electron doped infinite layer superconductor Sr$_{0.9}$La$_{0.1}$CuO$_2$. Structural and low-field magnetization study demonstrated that the superconducting quality of our samples were best among all kind of bulk samples reported until now. With these good samples, many new findings are under going by our collaborators and us.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2004년도 High Temperature Superconductivity Vol.XIV
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• pp.8-8
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• 2004

• E2M - 전기 전자와 첨단 소재
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• 제9권1호
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• pp.1-8
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• 1996

We investigated the effects of doping elements on the Bi-Sr-Ca-Cu-O ceramics. The doping elements can be classified into four groups depending on their supeconducting characteristics in the Bi-Sr-Ca-Cu-O structure. The first group of doping elements(Co, Fe, Ni and Zn) substitute into the copper site and can reduce the critical temperatures of the 2223 and 2212 phases. The second group of doping elements(Y and La) substitute into the Ca site and cause the disappearance of the 2223 phase and increase the critical temperatures in the 2212 phase. The third group of doping elements(P and K) have a tendency to decompose the superconducting phase and reduce the optimal sintering temperature. The fourth group of doping elements(B, Si, Sn and Ba) almost unaffected the superconductivity of the 2223 and 2212 phase.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1993년도 추계연구발표회 논문개요집
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• pp.38-39
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• 1993

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술회의 초록집
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• pp.12-12
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• 2010

The piezoelecric properties of $(K_{0.5}Na_{0.5})(Nb_{0.96}Sb_{0.04})O_3$+$1.2mol%K_4CuNb_8O_{23}$+$xmol%La_2O_3$ lead-free piezoelecric ceramics were investigated as a function x. These ceramics were fabricated by conventional ceramics processing. Piezoelectric constant ($d_{33}$) and piezoelectric charge coefficient ($g_{33}$) of x=0.2 mol% composition exhibited good properties of 160.3pC/N and 37.4($10^{-3}Vm/N$), respectively.

• 한국자기학회지
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• 제4권1호
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• pp.44-47
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• 1994

Laser ablation법으로 c-축 배향되도록 만든 Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7- .delta. / 박막으로 임계온도 근처에서 운반자들의 정보를 얻기위하여 Hall 효과를 연구하였다. 자기비저항은 Nernst 효과 때문에 자기장이 증가할 수록 offset 점의 온도가 낮았고, 자기비저항으로 부터 열자기적 효과를 고 려하여 계산한 Hall 비저항값과 실제 van der Pauw 법으로 측정한 Hall 비저항값을 비교해 본 결과 비교적 잘 일치하였다.

• 자원환경지질
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• 제31권4호
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• pp.297-310
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• 1998

Geochemical characteristics of environmental toxic elements at the Narim mine area were investigated on the basis of major, minor, rare earth element geochemistry and mineralogy. Ratios of $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ in soils and sediments range from 11.57 to 22.21 and from 1.86 to 3.93, and are partly negative and positive correlation against $SiO_2/Al_2O_3$ (3.41 to 4.78), respectively. These suggested that sediment source of host granitic gneiss could be due to rocks of high grade metamorphism originated by sedimentary rocks. Characteristics of some trace and rare earth elements of V/Ni (0.33 to 1.95), Ni/Co (2.00 to 6.50), Zr/Hf (11.27 to 53.10), La/Ce (0.44 to 0.55), Th/Yb (4.07 to 7.14), La/Th (2.35 to 3.93), $La_N/Yb_N$ (6.58 to 13.67), Co/Th (0.63 to 2.68), La/Sc (3.29 to 5.94) and Sc/Th (0.49 to 1.00) are revealed a narrow range and homogeneous compositions may be explained by simple source lithology. Major elements in all samples are enriched $Al_2O_3$, MgO, $TiO_2$ and LOI, especially $Fe_2O_3$ (mean=7.36 wt.%) in sediments than the composition of host granitic gneiss. The average enrichment indices of major and rare earth elements from the mining drainage are 2.05 and 2.91 of the sediments and are 2.02 and 2.60 of the soils, normalizing by composition of host granitic gneiss, respectively. Average composition (ppm) of minor and/or environmental toxic elements in sediments and soils are Ag=14 and 1, As=199 and 14, Cd=22 and 1, Cu=215 and 42, Pb=1770 and 65, Sb=18 and 3, Zn=3333 and 170, respectively, and extremely high concentrations are found in the subsurface sediments near the ore dump. Environmental toxic elements were strongly enriched in all samples, especially As, Cd, Cu, Pb, Sb and Zn. The level of enrichment was very severe in mining drainage sediments, while it was not so great in the soils. Based on the EPA value, enrichment index of toxic elements is 8.63 of mining drainage sediments and 0.54 of soils on the mining drainage. Mineral composition of soils and sediments near the mining area were partly variable being composed of quartz, mica, feldspar, amphibole, chlorite and clay minerals. From the gravity separated mineralogy, soils and sediments are composed of some pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, goethite and various hydroxide minerals.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
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• pp.57-57
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• 2005